code: def fnirs_evoked():
      """Create an fnirs evoked structure."""
      montage = make_standard_montage("biosemi16")
      ch_names = montage.ch_names
      ch_types = ["eeg"] * 16
      info = create_info(ch_names=ch_names, sfreq=20, ch_types=ch_types)
      evoked_data = np.random.randn(16, 30)
      evoked = EvokedArray(evoked_data, info=info, tmin=-0.2, nave=4)
      evoked.set_montage(montage)
      evoked.set_channel_types(
          {"Fp1": "hbo", "Fp2": "hbo", "F4": "hbo", "Fz": "hbo"},
          verbose="error",
      )
      return evoked
  
file_path: mne-python/mne/viz/conftest.py
imports: import os.path
  import numpy
  import pytest
  from mne import Epochs, EvokedArray, create_info, events_from_annotations
  from mne.channels import make_standard_montage
  from mne.datasets.testing import _pytest_param, data_path
  from mne.io import read_raw_nirx
  from mne.preprocessing.nirs import beer_lambert_law, optical_density
label_desc: Use image node_id 1 for calling a global function with example usage: fnirs_evoked() and returns: evoked